Rotary core drill



Patented Jan. v7, 1930 UNITED STATES y y '1,742,64r

PATENT oFFlcE ROTARY CORE DRILL' Application filed April 14, 1925. Serial No. 23,113.

My invention relates to rotary core drills, particularly of the type by whicha sample core is formed and extracted to determine the character of formation encountered.

It is a purpose of my invention to provide a core drill having core forming cutters which in operation are subjected to minimum wear so as to prevent the formation of a tapered core and to produce a core of uniform diameter thereby maintaining the strata of the core in their original relative positions so that the true character of the formation can be determined.

It is also a pur-pose of my invention to provide a core drill which'greatly facilitates the removal of the core from the barrel and in such manner as to eliminate the breaking, disintegration or in any way injuring the core when extracting the latter from the barrel.

A further purpose of my invention is the provision of a core drill' which operates to.

trim the core to a uniform diameter for free passage into the core barrel so that irrespective of any irregularity in the formation of the core due to wearing of the cutters, a core of uniform diameter with the strata thereof maintained in their original positions is insured.

I will describe only three forms of rotary core drills embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings Figure 1 is a view showing in vertical section one form of core drill embodying my invention in applied positionwithin a well.

Figure 2 is a'bottom plan view of the core drill shown in Figure 1 and with a portion thereof broken away. A y

Figure 3 is a vertical sectional viewtaken on the line 3-3 of Figure 1.

Figure 4 is a detail perspective view of one of the boring bits.

Figure 5 is a transverse sectional view taken on the line 5-5 of Figure 1. i

Figure 6 is a detail perspective view of the split sleeve embodied in the core drill shown in Figure 1. 50 Figure 7 is a view similar to Figure 42 showing another form of core drill embody,- ing my invention.

Figure 8 is a fragmentary vertical sectional view of athird form of core drill emsidered as made up of several sections of4 drill y pipe for connection of a string of drill tubing in the usual manner. Through the medium of a connecting sleeve 16, a tool head 17 is detachably connected to the lower end of the tubular shank 15, such head being provided with an annular collar 18 exteriorly threaded for engagement with the sleeve. The collar 18 is interiorly threaded to receive and secure therei an annular member 19 provided internal y with upwardly extending buttress threads 20 provided for the purpose of preventing downward displacement of a core from the core barrel. The core barrel designated at 21 is received within the bore of the tubular shank 15V and is threaded at its lower end for connection with the annular member 19, the latter being provided with an annular shoulder 22 on which the lower end of the barrel rests. This shoulder 22 is sufficiently wide to also form a support for a core receiving sleeve 23 mounted in the barrel 21. l This sleeveis made up of a plurality of, sections each of which is split longitudinallyv as indicated at 24 in Figure 6 and formed of a material having the requisite degree of resiliency to permit of its being expanded and contracted for a purpose which will be hereinafter described. v v

The up er end of the core barrel 21 is provided Awit acheckvalve 25 which permits water 'inv the barrel to be expelled into the shanka's the core moves into the barrel which prevents the flushing water entering the upper end'of the barrel.

As-illustrated to advantage in Figure 2, the tool head 17 is provided with a plurality of pockets or chambers 26 spaced circumferbers 26 are accessible from the bottom of 'the tool head, and as shown in Figure 3 each chamber contains a rotary cutter 27 rotatable on a stub axle 28 mounted in and disposed radially of the tool head as shown in Figure 2. The tool head is provided with a central bore 29 in vertical alinement with the core barrel 21 and annular member 19, and as shown in Figure 1 the cutters 27 are disposed so that their confronting sides are intangential relation to such bore. The inner ends of the stub axle 28 are concave as shown in Figure 2 in order that they will not gouge the core during rotation of the drill.

In the present instance I have shown the ltool head provided with three rotary cutters 27, and each cutter in the present instance is in the form of a relatively thick wheel having its peri hery provided with transversely extending ribs 30 which function as teeth for boring the earth in theformation of the core. As illustratedA in Figures 1 and 3, the mounting of the cutters 27 in the tool head is such that portions of their peripheriesat' all times project from" the bottom of the tool head so that the ribs 30 thereof may have boring engagement with the earth as the drill is rotated to form the core.

Between and insurrounding relation to the cutters are boring bits 31fhaving relatively broad bases suitably secured in recesses 32 in the bottom of the tool head and with their blades extending downwardly and outwardly beyond the periphery of the` tool head so that in the rota movement of the drill they will function to ore the hole. The blades4 of the bits extend in av counter-clockwise direction as when viewed in Figure 2 so that they cooperate in eifectin a drilling of the hole as will be understoo In operation, the bits 31 and the cutters 27 under rotar movement of the drill co-o erate in effecting a drilling of the hole, the its operating to drill the wall of the hole and a portion of the bottom and the cutters drilling a portion of the bottom and in such manner as to-form a core between the cutters. As the drill proceeds downwardly the core continues to be formed in this manner and directly beneath the bore of the tool head so that the core is free to pass upwardly into the bore and ultimately into the sleeve 23 of the core barrel 21. It is to be noted that fthe confronting sides of the cutters 27 operate in conjunction with the peripheries thereof in forming a core of uniform diameter and in such manner that the cutters are subjected to a minmum amount of wear. It will be therefore manifest that the original arrangement of strata forming the core is preserved during the 'passage of the core through the tool head and into the sleeve so that the true character of the earth formation can 'ily removed from the core barrel, it being understood that the sleeve has a sliding fit in -the core barrel. sleeve from the barrel 1t automatically expands by virtue of its split form thus releasing the core and ermitting the ready removal of the latter 1n the exact form in which it was introduced into the sleeve. In this manner the true character'of the earth formation is maintained during the formation f and removal ofthe core from the drill.

In order that the rotary cutters 27 be properly flushed at all times during the operation of the drilling, the collar 18 is provided with ports 33 which provide communication between the shank and the core barrel and the several chambers or pockets 26 so that. flushing water introduced into the shank will findv ready access to the several chambers 26.

Referring now to Figure 7, I have here` shown another form of core drill embodying my invention which is identical to the core drill first described with the exception'that concavo-convex disks 34 are used in place of the rotary cutters 27. These disks have their cutting edges4 disposedtangentially of the4 bore 29 of the tool head and similarly-to the cutters 27 the project from the bottom of the tool head or engagement with the earth in the formation ,of the core.

U on removal of the The disks are disposed in pockets 35 and rotatably mounted on stub axles 36, the axles bein insertable into the heads through openings 3 I extending inwardly from the peripheries of the head. The mounting and arrangement of the severaldisks is such that they not only co-operate to form a core which ultimately passes upwardly into the sleeve of the core barrel but they operate to trim the core as it passes through the bore of the tool -head whereby the formation of a core of uniform diameter is insured.

Referring now to Figure 8, I have here shown a third form of core drill embodying my invention which comprises a tool head 38 associated with the tubular shank and core barrel in the same manner as the other tool heads. The head 38 is formed with a central bore 39 in vertical alinement with the core barrel, and extending outwardly from the bore are pockets 40 in which trimming wheels 41 are rotatably mounted. These wheels 41 are mounted-on vstub axles/12 secured within the tool head, the wheels are arranged withtheir confronting sides Hush with the bore 39 so as to have contact with the core as it passes upwardly throu h the bore.

In this embodiment of my invention, the

iso

ranged bits 4?; secured to' and depending from" the bottom of the tool head and also functioni ly. As a result of this wear, a core of taperedform is produced or a form whichv exceeds in diameter that of the bore so that in en. tering the'bore a constriction of the core is eected which operates to destroy the original positionsoiiA the strata forming the core so that the true character of. the formation can not be subsequently determined. In order to overcome this difficulty and produce a core which can readily pass through the bore` of the tool head without disturbing the original character ofthe formation, the

' .wheels 41 are provided, and as shown these with a plurality of downwardly openingv .Wheels are disposed above the bits 43 so that the vconfronting sides under the rotative movement of the drill will operate to trim the core to such diameter that it can pass freely through the bore into the core barrel.

In Figure 8, I have shown the tool head 38 provided with ports 44 through which a ushing, water finds access to the pockets 40. Other ports 45 are formed in the tool head so that the water supplied to the pockets can ind its way downwardly to points between the bits 43.

Although I have here shown and described only three orms of rotary core drills embodying my invention, it is to-be understood that various changes and modifications ,may be made therein without departing from the spirit of the invention and the spirit and scope of the appended claims.

What I claim is:

l; A'core drill comprising a tubular shank adapted to be connected-to a rotary drill pipe, a sleeve connected to the lower end of the shank, a tool head having an annuluar externally threaded collar threaded into the sleeve and provided with an internally threaded portion, lan annular member threaded into said portion and having an annular shdulder, a core barrel threaded into the annular member and engaging said shoulder, said barrel having a centrally disposed core receiving bore and provided around the bore pockets arranged tangentially with respect to the axis of the barrel, horizontal stub axles secured to the barrel extending radially into said pockets, relatively thick cutter wheels rotatably mounted on the axles `and having peripheral transversely extending ribs to form teeth, said wheels projecting below the tool head so thattheir teeth are adapted for boringV engagement with the earth to'form a core, andl a plurality cut# ters having relatively broad bases secured to the head and the blades of which project below the rotary cutters andv beyond the periphery of the tool head. 2. In a core drill, a tool head having a cor receiving bore, boring cuttersfixedly secured to the head fon rotation therewith, and core trimming elements mounted to rotate about horizonal axes in the head above the'lixed cutters and comprising wheels having their confronting side faces disposed ata tangent to a circle defining the circumference of the tangentially of the bore so that their confronting side faces are adapted to have contact with a core received in the bore, and a plurality of cutters fixed to the head in alternate relation to the rotary cutters and having cuttinr blades,the outer ends of which are disposed 2beyonda circle defined'by the outer sides of the rotary cutters and the inner ends of which are disposed Within said y circle, the cutting lblades of the last mentioned cutters being radially arranged and inclined downwardly and forwardly in the direction of rotation of the head, the blades pesenting horizontal and vertical cutting e ges. l

y ARTHUR LEON ARMENTROUT. n 

